4WDKING Rechargeable Personal Air Purifier with HEPA Filter for Outdoor

Just received this and charged it, and letting it blow out for an hour to remove plastic vapors from the hose like the instructions say. (It does smell very plastic/chemical at first.) The airflow rate feels good and I don't feel any leaks from the case or hose. It's not loud at all, a very slight motor sound with a little more air sound. I can tell it's on if I listen for it, but it's not intrusive. Case is actual metal, seems strong, and weighs much less than I was expecting it to from the appearance, slightly lighter than my TV remote with batteries in it. It doesn't come with a charger but the port is micro-USB, so compatible chargers should be plentiful. The two screws holding the front plate on are very tight though, made removing the cover to take off the plastic shipping barrier from the battery difficult. It's not something I'll need to open often given the estimated filter life, and they may be looser now, but I'm concerned they may not last. I don't think the threads are stripping but the Phillips heads are a bit worn after just one time. I may replace them with flathead slots to make opening it easier. The on button is a bit sensitive and nearly flush with the surface, just something to remember when grabbing the unit to check that you didn't turn it on or off or change the blower speed by accident. If they make a version 2, a raised ridge around the button to prevent accidental presses would be a suggestion. Will update after getting a chance to actually use it, but so far so good. The masks it came with seem to be good quality KN-95. Since it's a powered air feed system blowing clean air inside rather than requiring you to suck air in through the mask material by lung power, they should clog less often than the same masks used as an unpowered KN-95. Fit will be important to protect others though, if they don't sit well on your face there could be some leakage of your breath. Not much else to say about them. The hoses are soft but seem pretty resistant to kinking. They are easy to get on and off the connectors. They're an unusual size, the seller answered a question with the exact dimensions previously. I was hoping they'd be the same diameter as a CPAP hose but they are not, they're smaller.I don't know what their lifespan is yet but replacement hoses are available from the seller and not expensive. I would like to get some more replacement connectors too but haven't found them yet. It's not clear from the item page, but one of the connectors is for joining the long and short hose into a longer single hose, and the other is for attaching the hose to the mask. The mask adapter seems to rely on the hole in the mask being slightly smaller than the connector so it stays tight. It won't and can't fall off, it just could leave a gap and leak if you're not careful about cutting. One mask is pre-cut and the others are not. A little sticker is included to trace the hole size around. Besides the screws, the main issue so far is the instruction manual. The English isn't bad, and it gives some good tips I wouldn't have thought of (like keep it in a pocket if you use it in really cold weather or it will feed you unpleasantly cold air, and tie a cloth over it to extend the HEPA filter life in dirty environments), but it doesn't explain a lot of common things, like how long to charge, or what the 3 LEDs on top mean when they glow or blink in certain colors. All three blink red when charging, and glow solid at what I'm guessing to be full charge. Charging didn't take long but I don't know how empty it was fresh out of the box. They don't seem to count down to full charge by blinking or glowing separately, they just all blink and then all glow solid. When running two of them are green, and one is orange (seems to be a mix of red and green). There's no change in them at different fan speeds. Maybe they're indicating the remaining battery level but I haven't gotten it down past the first third yet? Anyway, will update later, but found this interesting enough to write a review of what I've seen of it so far.

Great, great product. Use it every time I go to enclosed public places. It has protected me all these years. Battery lasts as specified. I have one unit that keeps working excellently after 6 years of use, just needing to replace the mask from time to time and a new filter after 500 hours. I bought a second one to have on hand. I got one as a gift from a different company, and it stopped working from the very start.

Caveats Not designed for viral protection . Powered air creates positive pressure that amplifies all face masks fatal flaw, unfiltered exhalation leakage. So wearer gets gobs of filtered air , but increases exposure risk to those around you. We try to mitigate this and minimize leakage with simple modifications that will work to improve any mask. Tighten mask to face with any mask frame, home made bracket frame made from 1/2" garden ties, and most efficent 8-10" cut off nylons panty hose used over entire mask. Close any gaps 3/8 closed cell foam adhesive weather stripping applied to inside edge especially around nose piece. We add standard mask exhaust valve with filter material fixed to inside of valve to provide lower bypass pressure. any mask with exhaust valve should have filter material fixed to inside. Otherwise it is just a virus concentrating and aiming device. All brands claim h13 hepa filter. Some have niosh or china certification print on filters. We add layer of Merv 16 Filti face mask material from filti.com or any of electrostatic melt blown polypropelene available here on amazon on top of hepa filter. Setting aside filter QC issues, non compliant materials , or unseen defect to these tiny hepa filters we consider this an imperative redundancy for viral filtration. It probably brings filtration to N99 level and reduces air flow volume 10-15%. We have been modifying all 4 brands of these for mask intolerant, exercise demand, and high exposure users. There is little functionality difference between brands. The airdog has round shape and also makes a small desk top unit The simple advantages, The models with KN95 mask fit most faces very well. great fresh air source for smoke and pollutants out of box good experience with battery life, component quality, adequate airflow up to moderate exercise. these make a great adjunct without tubing worn around neck blowing filtered cooling air while wearing a normal mask underneath a face shield. All materials except Filti nano filter material available on amazon. an inventive negative/positive electric demand valve would make these a life saver for frontliners who deserve a lot better than a cotton bandana.

As a person with extreme allergies. This has saved me. Not even kidding. I wish I found this sooner. It’s like breathing fresh air. Thank you!!

This device is a gift from heaven for people who have a hard time breathing through ordinary masks. It works by pulling air in through a 99% HEPA filter piping it into a KN-95 mask and then out through the mask. There are 3 speeds so as you need more air you can increase the speed and airflow. It is not industrial quality but if you care for it the device is reliable and easily recharged via USB. And you can get extra HEPA filters. You can use ANY mask just by cutting out a 1/2" hole and affixing the hose port to the mask. Now comes the down side. The device creates a positive pressure inside the mask. It protects the wearer beautifully. BUT that same pressure may reduce protection for others. Why if the mask is KN-95? It's because the positive pressure has to go somewhere and it has two choices... through the KN-95 mask filter or find a place that is easier to go through like a small opening on the side of the mask. This can cause your unfiltered exhalation to escape the mask. If you socially distance and stay away from people, this should be no problem. if you do not have COVID it is no problem. But if you have COVID and can tolerate a KN-95 mask, that would be more protective of others so long as the mask is well-fitted. I go out once a month and for me this is heaven sent.

Works well. I modified it in two ways. I made a 1" wide nylon strap at ACE with a clip in buckle to make it practical to wear around my waist. I got a non-rebreathing oxygen mask and removed the main O2 fitting. (Mountain Medical, $2.80 per mask plus shipping.) I also put a piece of tape over the right side vent holes. This works. The silicon tube fits perfectly into the main O2 fitting in front. This mask is comfortable to wear for a couple hours at the range. People can see your face through it, and you don't have creases dug into your face like the poly-masks that comes with this unit. The elastic strap for the O2 mask isn't perfect, but it works well enough. The filter definitely is working. 2 sessions of a couple hours and it's visibly darkened in the center of the HEPA filter. This mask works with my range eyegear. It's comfortable.

This is a great system. It's the only one that really works.

I really wanted this to work. If you blow enough filtered air into a mask, it keeps unfiltered air out of the mask. But the air needs to be high enough flow, and it needs to be properly filterd .Unfortunately, the output of the blower isn't 99.9% like the listing claims, it's more like 75%. Massive difference. It's as if nobody actually tested the unit *as a whole* (not just the filter media on its own in a lab) with measuring instruments before marketing it around the world. I'm not sure why the output of the blower has such low total filtration efficiency. It could be poor filter media, or the filter and blower may not be properly sealed, allowing unfiltered air to leak into the output. Or some combination of both. Ultimately it doesn't matter what is causing the poor total filtration efficiency, only that it is low, as in leaky surgical mask low.

Like the size and weight of this air purifier in comparison to another I bought ( was bigger , the on/off button broke, was a bit more expensive, the filter worked though )however it does not properly filter out scents. I’m going to try cutting an alternate filter material to replace the one it came with in hopes that that’ll work.

マスクが厚く息が吐き辛い。 故に酸素チューブ、呼吸チューブを使える様にし、通常のマスクに替えて使用してます。

It is nice and great for protection and infection control.

I simply can't wear a mask. I just panic. However, a friend told me about this one so I bought it to give it a try. It's the best. The Pump is NOT loud as I read in some reviews. The hose it NOT flimsy as I read in another review. There ARE more than one grommet in the package, as a matter of fact there are 4. and there are plenty of masks too. I'm very happy with this purchase and am so pleased I can wear it without panicking and feeling I have to GET IT OFF ME. I played around with the different levels of air flow and really, level one is enough for me so the battery charge will last lots longer. A big than you to Aurora and a big than you to my friend for suggesting this. It's a game changer for me.

Está muy padre este cubrebocas, si funciona y el ruido que hace el filtro no es tan fuerte aunque tiene 3 velocidades, estaría mas padre si la manguerita pudiera estar mas en medio porque cuando sale el aire lo sientes de un solo lado.